I think Oxygen is the best answer.
Answer:
Option A.
Explanation:
Air pressure decreases with increasing altitude.
In this scenario,I guess the answer is roughly around 300 children die every year from the diseases in which the vaccinations are available. Hope this is the correct answer then and would surely be of big help to you then.
Answer:
an S strain and mix it with cells of an R strain
Answer:
D. Bear
Explanation:
The answer is bear because a bear is an animal. Everything but animals can carry out cellular respiration.